Furnace for smelting ores.



C. J. BEAVER & E. A.'CLAREMONT.

FURNACE FOR SMEETING ORES. VAYPLICATION' HLED APR. n. 1916.

3 SHEER-SHEET 1.

LMSEQS, Patented M. 23, 19-17.

C. J. BEAVER & E. A. CLAREMONT.

FURNACE FOR SMELTING QRES.

APPLICATION FILED APR. 11. 1916.

' LMBJWQQ Patented Oct. 23,1917;

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APPLICATION FILED APR. 17' 1916- I 1,243,798. i Patented Oct. 23, 1917.

3 SHEETS-SHEET a.

. p' NraEn sraa ns 'EEATEET oEEic cnAaLEs JAMEs BEAVER AND ERNESTALEXANDER, cLAEEMoNT, 0E cHEsHIaE,

ENGLAND. r

EIiRNAGE Eon si/iELTING oEEs.

Specification of Letters Patent. 0

Application filed April 17, 1916, Seria1No.9 1,760

T0 aZlw/wm it may concern:

Be it known that We, CHARLES JAMES BEAVER, and ERNEST ALEXANDERGLAREMONT, bothsubjects of the King of England, residing at Cheshire, inEngland, have invented certainnew and useful Improvements in Furnacesfor Smelting Ores, of which the following is a specification; I

This invention comprises an improved furnace for smelting oresparticularly rich lead ores but not suitable for all ores.

In the reverberatory furnaces for smelting rich lead ores now invogue,the heat and products of combustion are conducted into and through ahorizontal chamber, 011 the floor of which the ore is placed, and thenceto the chimney shaft. The chamber 'is provided with ports or doors bywhich air can at will be admitted into the chamber. The ore is heated upto a temperaturebetween 500 C. and 600 or thereabouts in an oxidizingatmosphere produced by the introduction of air and when suflicient timehas elapsed for the sulfur and other impurities to be oxidized andgasified and taken off, the air inlets are closed and the heatincreased'up to or about 1000 C. in a nonoxidizing atmosphere producedby the productsof combustion and of the smelting reaction ffilling thechamber.

During both processesthe ore is rabbled by hand through doors or otheropenings in the chamber.

In such a furnace difficulty is experienced in controlling thetemperatures required and there follows an uncertainty in results. It isgenerally necessary to treat the resulting slag a second time to extractall the lead, a large percentage of which after the first treatingremains trapped or bound in the slag and a sensible loss of lead takesplace in the form of volatilized lead or lead compound which escapes bythe chinmey shaft.

The object of our invention is to enable the smelting of such ores to becarried'on continuously as one. operation the ore passing from onetemperature and one atmosphere to the other temperature and otheratmosphere in a continuous passage through the furnace to have thetemperature and atmosphere under better control and to avoid the loss intime, labor and material attendant on the present method.

We construct a furnace containing a long chamber preferably arrangedhorizontally,

Patented Oct, 23, 1917..

heated externally we out the products of combustion passing through thechamber) as by gases of combustion from a furnace which enables the endof the chamber into which the ore is introduced or fed; (hereinaftercalledthe I front part) to be heated to and maintained ata temperature;of from 600 C. to 650 C. while the other or farther end thereinaftercalled the farther part) c'an be heated toand maintained atatemperature'of or' above 900 C. as may be necessary for correcttreatment of theore charge andprovided with means and ,mechanism hereinafter described. The front part of the chamber isprovided with means forintroducing air and with means for extracting and carrying away'airgaseous fumes and products said means being so arranged that the airintroduced after performing its functions is extracted Withouttraversing the farther part ofthe chamber. For example we may arrange apipe orpipes across the center of the chamber, with holes toward thefront part of the chamber and other openings in the Walls of the frontpart through which air can be injected or drawn and at the end of thefront part an outlet furnished .with a fan or other form of suctiondevice. The interior of the chamber is furnished with means such asautomatic rabbles or rakes for turning and shifting the ore and slowlymoving it along the chamber from the front part to' the farther part andassisting in the separation of the lead from the slag. The front part isprovided with an inlet opening which may take the form of a hopperthrough which the ore to be treated is introduced or fed. Thefartherpart is provided with means such as the sloping of parts ofthe hearth orfloor and catch pits or wells to collect the molten lead and slag and topart of the chamber between the front part and the farther part of thechamberto assist in preventing air and gases in the front part frompassing to the farther part.

In the accompanying drawings is shown an example of a furnaceconstructedin accordance with our invention,

Figure 1 represents an end elevation of the back end of the furnace.

Fig. 2 is a side elevation of the furnace.

Fig. 3 is a cross section on line AA of Figs. 2 and 6.

Fig. 4: is a longitudinal section on line B, B of Figs. 1, 3 and 5.

Fig. 5 is a cross section on line C, G of Figs. 2, l and 6.

Fig. 6 is a sectional plan in the line Fig. 9 paratus and Fig. 10 alongitudinal section on line G, G of Fig. 7.

Figs; 1, 2, 3, 4, 5 and 6 show the construc tion of a suitable type offurnace in which the fines and dampers are arranged so that the requiredvariation of temperature may be attained in the interior of the furnace.

a is the combustion chamber, 6 is a longitudinal flue passing laterallyof the chamber 25 at the same side as the fire connecting with flues 6across the roof of the chamber all of which connect with a longitudinalflue b on the opposite side of the chamber and are severally controlledby dampers c the flue 6 leading into the vertical flue b which via thefines 6* and Z9 under the hearth leads to the chimney Z). Z is theexternally heated chamber in which the smelting is effected the wallsand roof of which are preferably made of suitable refractory materialand the hearth i lined with material such as plumbago or the slag.resulting from the complete smelting of lead ore. e are air ports orinlets and e is a suitably perforated or slotted pipe fixed transverselyacross the chamber d, all provided with valves (not shown) to enable airin such quantities as desired to be introduced into the chamber. f is atightly fitting door at the back end of the furnace for cleaning,repair, observation and emergency manipulation or corrective purposes. 9is an out let pipe preferably furnished with a fan or other form ofsuction device 9 by which air is drawn in through the inlets e or 6 andwhich outlet pipe 9 may have a branch 9 to the back part of the chamberto bypass gaseous products, formed therein and maylead to scrubbers,towers or the like for treating and utilizing waste or by-products. 72,is a hopper for introducing the charge which when not in use is inclosedand is ap proximately airtight. as is a division wall constructed in theupper part of the chamber (Z above the pipe 6 as shown in Figs. 3 and 4.This wall may be so constructed as to contain ports m regulated bydampers x in place of the pipe 6 The object of this wall is tofacilitate the maintenance of different atmospheric conditions at thefront part and farther end of the chamber d. The hearth i is suitablyshaped to avoid lodgment of parts of the charge as shown for instance atj at the front end of the furnace where the change enters and along thesides as at j. A part t of the hearth is raised above the general leveltothe height of the slope y' This part 25 has a flat horizontal surfacein the same plane as a height of said slope y' and has a curve orundulating forward face forming a vertical wall 6 which consists indirecting the charge to the sloping surface j hereinafter mentioned. Therear edge of said part t means the inclined vertical edge of the slope9' as shown in Fig. 3. The part of the hearth toward the rear end of thechamber past the lines o and v in Fig. 6 is gradually sloped awaylongitudinally and transversely or obliquely as at 7' and 7'respectively. toward one corner which constitutes the lead well Z toreceive the separated lead, while in the opposite corner a pit 7c isformed to receive the separated slag drawn up the slope j by the rabblesor rakes hereinafter described.

Figs. 7, 8 and 10 are generally similar to Figs. 3, 6 and a respectivelybut show suitable mechanical rabbling or raking apparatus for themanipulation of the charge. Many known forms of mechanical rakingapparatus could be used'but we illustrate two forms which we prefer asbeing most suitable to the physical state of the charge,

0 are rakes or rabbles consisting of arms or blades mounted on rotatableshafts. The arms or blades maybe in the form of sections of screwthreads of suitable size for the degree and character of movementrequired in the various parts of the chamber. For instance at the frontend of the chamber where the charge is introduced, the arms 0 preferablyform small sections of screw threads acting as fingers or pickers,because the charge is 1n a powdery condition while passmg through thefront end ofthe chamber, but at a later stage when the charge is r in asemi-plastic condition in the smelting Zone, the arms 0 preferably formlarge screw sections, while toward the end of the furnace on the slopeof the hearth above referred to, complete or almost complete screws maybe used in order to pass the charge laterally on to the slope j In Fig.8 the positions of some of the rabble shafts are indicated by dottedlines m and in Fig. 10 dotted circles n indicate the rotary paths of therabbles. The speed and direction of rotation may be varied as required,and the rotary movements may be either intermittent or continuous. 29designates a form of mechanical raking arrangement on the slope j whichwe preferfor the final stage of the manipulation of the charge. A sideelevation of the device 39 is shown in Fig. 9' in which a series of arms9 are mounted on cross bars 7" and suitably spaced thereon so that thepaths of successive arms do notcoincide.

The action of the furnace and its mechanical apparatus is as follows 2--The charge of lead ore is fed in crushed or'powde'red form into thefurnace through hopper hand is carried along by the rabbles or rakes anddistributed over the hearth so that it is eXposedin the front part ofthe chamber to the required temperature 600 to 650 centigrade and therequired atmospheric or oxidizing conditions for the roasting of' theore, the temperature being adjusted by the dampers c and the atmosphereby the air inlets e or e Owing to the arrangement of the various partsand features of the furnace the treatment of the ore inthe front part ofthe chamber is distinct and separate from the treatment in the fartherend. The air entering through the inlets in the front part and the fumesand gaseous products formed are carried away through the pipe 9 and donot penetrate to the farther end of the chamber (Z. The gaseous productsfrom the farther end may be partly drawn through the by-pass g to thepipe 9 instead of traversing the front part.

The speed of shifting of the charge in the traverse 'of the same throughthe front part of the chamber is regulated so that the charge issufficiently roasted before passing into the farther end. In the fartherend of the chamber to which air is not admitted but which is filled withthe non-oxidizing fumes given oft by the treated ore, the temperature isincreased to the required extent in order to bring about the requiredreaction between the lead sulfid, lead oXid and lead sulfate produced bythe roasting process. In this part of the process (as is well known) thecharge tends to become plastic but by close control of the furnacetemperature and suitable manipulation, it is prevented from becoming toosoft. Other control or correction of the smelting reaction or of theplasticity of the charge may be made if required by means known in theart, for instance, by the addition of powdered coal, lime, etc.,introduced through the door 7. The action of the rabbles, in addition tocausing the charge to traverse the hearth forms paths therein whichallow the lead produced by the reaction to become disentangled from theresidual slag, and on reaching the slope 9' a proportion of the metalliclead is free to run down into the lead well Z. The slag together withseparated lead is then carried by the mechanical raking device 20 up theslope 7' in such a manner that the plastic mass while being drawn up theslope is closely channeled by the arms q thereby allowing the remainderof the lead to be freed from slag and to run down into the lead well Z.The'residual slag gradually reaches the upper ridge of the slope j andfalls intothe slag pit 7a. The lead on one side of the furnace and theslag on the other are drawn off preferably 1 at intervals throughsuitable tapping holes 8 and in a well'kn'own manner.

stantially higher temperature than the smelting chamber of the feedportion thereof, controllable means for admitting eXte-- rior air directto said feed portion'and means for extracting products of combustionfrom said feed portion and substantially preventing access of air or thesaid products to said discharge portion.

2. In a furnace forthe continuous smelting of ores in a singleoperation, the combination of a relatively long externally heatedsmelting-chamber, means for feeding a charge of ore into one portion ofthe chamber, means for maintaining the other portion of said chamber ata substantially higher temperature than said feed portion thereof,controllable means for admitting exterior air direct to said feedportion, means for extracting products of combustion from said feedportion and substantially preventing access of said products to saidother portion, means for automatically rabbling the ore and shiftingsame along the chamber to the 'farther end thereof, and means at saidfarther end for separating the molten metal from the slag.

3. In a furnace for the continuous smelting of ores in a singleoperation, the combination of a relatively long externally heatedsmelting-chamber, a hearth in said chamber.

means for maintaining one portion of said chamber at a substantiallyhigher temperature than the other portion thereof, controllable meansfor admitting air to said other portion,'means for extracting productsof combustion from said last mentioned chamber-portion and substantiallypreventing access of said products to said first mentioned portion, apartition wall partially dividing the chamber into the two portionsaforesaid,

means for feeding a charge of ore into the chamber at one end, means forautomatically rabbling the ore and shifting same along the hearth to thefarther end of said chamber, and means at said farther end forseparating the molten metal from the slag.

4C. In a furnace for the continuous smelting of ores in a singleoperation, the combination of a relatively long externally heatedsmelting-chamber, a hearth in said chamber having reversely inclinedsurfaces at the rearward end, means for maintaining the forward portionof said chamber at a substantially lower temperature than the rearwardportion thereof, a partition wall partially dividing the chamber intothe two portions aforesaid, means for feeding a charge of ore into thechamber at its forward end, and means for automatically rabbling the oreand shifting same along the hearth to the rearward end of said chamber,said rabbling means conducting the slag up said inclined surfaces whilepermitting the molten metal to gravitate down same.

5. In a furnace for the continuous smelting of ores in a singleoperation, the combination of a relatively long externally heatedsmelting-chamber, a hearth in said chamber, means for maintaining oneportion of said chamber at a substantially higher temperaturethan theother portion thereof, controllable means for admitting air laterally tosaid other portion, a valved pipe extending across the chamber andhaving openings into that part thereof to which air is admitted, meansfor extracting products of combustion from said last mentionedchamberportion and substantially preventing access of said products tosaid first mentioned portion, a partition wall partially dividing thechamber into the two portions aforesaid, means for feeding a charge ofore intothe chamber at one end, means for automatically rabbling the oreand shifting same along the hearth to the farther end of said chamher,and means for separating the molten metal from the slag includingrelatively sloped parts of the hearth up which the slag is conducted bythe rabbling devices and down which the molten lead gravitates.

In witness whereof we have signed this specification in the presence oftwo witnesses.

Witnesses L. L. BEoH'rAN,

C. A. NEALE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

- Washington, D. G.

